The regional group of Continental Europe includes the members of the former Union for the Co-ordination of Transmission of Electricity (UCTE). The UCTE was founded in 1951 as the Union for the Coordination of Production and Transmission of Electricity consisting of an interconnected companies from Switzerland, Francia and Germany. Over the time, most of TSOs of Continental Europe joined the association. In 1999, UCTE re-defined itself as an association of TSOs. Before merging to ENTSO-E, UCTE represented 29 transmission system operators of 24 countries operating the synchronous grid of Continental Europe.[16]

The Nordic region consists of Finland, Sweden, Norway and Eastern Denmark, the members of the former Nordic TSO association NORDEL. NORDEL was founded in 1963 for co-operation between the TSOs of Denmark, Finland, Iceland, Norway and Sweden for a further development of an harmonized Nordic electricity market.[19]

The Baltic region consists of Estonia, Latvia and Lithuania. Before creation of the ENTSO-E, the Baltic TSOs were members of the Baltic Transmission System Operators association (BALTSO). BALTSO was founded on 30 March 2006.[20]

In order to ensure a working European power grid, the operating frequency is defined by a standard of 50 hertz. As electric generation and consumption differs, the power transmission grid has to be balanced. There should be the same amount of input and output. Nevertheless changes in the frequency may occur if supply or demand exceeds its counterpart. In case of too much supply the frequency will increase, while in case of too much demand it will decrease. The main task is to keep the frequencies of all five synchronous areas balanced around the 50 hertz standard to ensure a safe power supply.[21]

An open European electricity market needs a considerable electronic data interchange between all market participants in order to improve the coordination between different inter-country systems. The aim of the ENTSO-E is to offer all participants the necessary information of the existing EDI standards and their specifications. In association with ebiX and EFET (European Federation of Energy Traders) ENTSO-E maintains a Harmonised role model for the European electricity market.[22]

The ENTSO-E will publish a ten-year network development statement, which ought to ensure the reliability and security of electric energy supply in Europe. An adequate grid should be available for the functioning of the European electricity market. The committee will introduce technical rules and standards related to the planning of transmission systems and new technical concepts within R&D-activities. Furthermore it will focus on facilitating the exchange of information about efficient asset management, system technology and critical infrastructure protection among members. In order to fulfill its duties and tasks, the committee will investigate and develop long-term and medium-term system extension strategies, draw system studies and collect data relevant for system development.[23]